Last year's Spanish MotoGP at Jerez was a memorable event for then rookie Johann Zarco, who finished as the top Yamaha rider for the first time in his young premier-class career.
"We'd been penalised more than we thought by the absence of the winglets and also Jorge realised the bike was more complex than he had thought" - Paolo Ciabatti, Ducati.
Pramac Ducati rider Danilo Petrucci was fifth fastest in free practice at Jerez on Friday but says the tight turns are causing problems for the Desmosedici.